ecomike wrote:I wonder why there is so much calcium in the sample????
Remember, NAPA 15w-40 is a diesel specific formulated motor oil. It must have a much greater capacity to keep soot in suspension than a gasoline oil.
Elemental Analysis by ICP (inductively-coupled plasma) detects up to 24 metals, measuring less than 5µ in size, that can be present in used oil due to wear, contamination or additives.
Wear Metals include iron, chromium, nickel, aluminum, copper, lead, tin, cadmium, silver, titanium and vanadium.
Contaminant Metals include silicon, sodium, potassium, molybdenum, antimony, manganese, lithium and boron.
Additive Metals include magnesium,
calcium(a detergent dispersant additive), barium, phosphorous and zinc.